docs: def get_resources(self, types=None, names=None, languages=None):
          """
          Get resources.
          
          types = a list of resource types to search for (None = all)
          names = a list of resource names to search for (None = all)
          languages = a list of resource languages to search for (None = all)
          Return a dict of the form {type_: {name: {language: data}}} which 
          might also be empty if no matching resources were found.
          
          """
          return GetResources(self.filename, types, names, languages)